Hexametaphosphate-Coated Snack Biscuits Significantly Reduce Calculus Formation in Dogs

We conducted a clinical trial in beagle dogs to determine the impact of a popular snack-type biscuit and an experimental biscuit coated with 0.6% sodium hexametaphosphate (HMP) upon calculus formation. The study used a crossover design evaluating each dog on each regimen with 4-week test periods, each of which began with a dental prophylaxis (scaling and polishing). The dogs were provided a single daily feeding of dry chow followed 4 hours later by either no snack or a snack comprised of two or four conventional biscuits, or two HMP-coated biscuits. As compared to the no-snack regimen, feeding two or four conventional bone-shaped biscuits exerted no significant effect upon calculus formation, while the similar feeding of two HMP-coated biscuits significantly reduced calculus formation by 46%.

Lower limb blood flow and mean arterial pressure during standing and seated work: Implications for workplace posture recommendations

Sit-stand workstations are a popular workplace intervention. Organizations often require a medical professional's guidance for implementation. Therefore, it is important to understand potential negative outcomes associated with standing work, such as lower limb discomfort and peripheral vascular issues. The objective of this study was to compare changes in lower limb discomfort, blood pressure and blood flow accumulation during a light-load repetitive upper limb work task accomplished from seated and standing postures. At the Jewish Rehabilitation Hospital (Laval, Quebec, Canada), 16 participants were outfitted with Laser Doppler Flow (LDF) electrodes to measure blood flow in the lower limb, and a sphygmomanometer to measure lower limb mean arterial blood pressure (MAP). Participants completed simulated work over 34 min in standing and seated conditions. Repeated measures ANOVAs (Posture x Time) were used to assess the differences. There were significant effects for both Posture (p = 0.003) and Time (p = 0.007) for LDF-measured of blood flow accumulation in the soleus and the foot, with a mean increase of 77% blood flow over time in the standing posture, when compared to seated work. There was a significant 'Posture × Time' (p = 0.0034) interaction effect and a significant Posture (p = 0.0001) effect for MAP, with higher values in the standing posture by a mean of 37.2 mmHg. Posture had a significant effect (p < 0.001) on lower limb discomfort, with standing posture reporting higher levels. These results suggest that recommendations for using static standing work postures should be tempered, and physicians' guidance on workstation changes should consider the impacts on the lower limb.

A case study detailing key considerations for implementing a telehealth approach to office ergonomics

Telehealth approaches to delivering ergonomics assessment hold great potential to improve service delivery in rural and remote settings. This case study describes a telehealth-based ergonomics service delivery process, and compares in-person and telehealth-based ergonomics approaches at an Alberta-based non-profit advocacy group. This project demonstrates that telehealth approaches to ergonomics do not lead to significantly different scoring outcomes for assessment of ergonomics issues, when compared to in-person assessments. This project also outlines the importance of live real-time video conferencing to improving communication, attaining key assessment information, and demonstrating ergonomic adjustments. However, some key considerations of bandwidth and hardware capabilities need to be taken into account. Key communication strategies are outlined to improve rapport, maintain employee confidentiality, and reduce client anxiety around telehealth ergonomics assessments. This project provides further support for telehealth approaches to office ergonomics, and outlines some key implementation strategies and barriers that should be considered.

Genome-wide association study of shared components of reading disability and language impairment

Written and verbal languages are neurobehavioral traits vital to the development of communication skills. Unfortunately, disorders involving these traits-specifically reading disability (RD) and language impairment (LI)-are common and prevent affected individuals from developing adequate communication skills, leaving them at risk for adverse academic, socioeconomic and psychiatric outcomes. Both RD and LI are complex traits that frequently co-occur, leading us to hypothesize that these disorders share genetic etiologies. To test this, we performed a genome-wide association study on individuals affected with both RD and LI in the Avon Longitudinal Study of Parents and Children. The strongest associations were seen with markers in ZNF385D (OR = 1.81, P = 5.45 × 10(-7) ) and COL4A2 (OR = 1.71, P = 7.59 × 10(-7) ). Markers within NDST4 showed the strongest associations with LI individually (OR = 1.827, P = 1.40 × 10(-7) ). We replicated association of ZNF385D using receptive vocabulary measures in the Pediatric Imaging Neurocognitive Genetics study (P = 0.00245). We then used diffusion tensor imaging fiber tract volume data on 16 fiber tracts to examine the implications of replicated markers. ZNF385D was a predictor of overall fiber tract volumes in both hemispheres, as well as global brain volume. Here, we present evidence for ZNF385D as a candidate gene for RD and LI. The implication of transcription factor ZNF385D in RD and LI underscores the importance of transcriptional regulation in the development of higher order neurocognitive traits. Further study is necessary to discern target genes of ZNF385D and how it functions within neural development of fluent language.

D-cycloserine or similar physiochemical compounds may be uniquely suited for use in Bacillus anthracis spore decontamination strategies

AIMS

As observed in the aftermath of the anthrax attacks of 2001, decontamination and remediation of a site contaminated by the accidental or intentional release of Bacillus anthracis spores is difficult, costly and potentially damaging to the environment. The identification of novel strategies that neutralize the threat of spores while minimizing environmental damage remains a high priority. We investigated the efficacy of d-cycloserine (DCS), an antibiotic and inhibitor of the spore-associated enzyme (alanine racemase) responsible for converting l-alanine to d-alanine, as a spore germination enhancer and antimicrobial agent.

METHODS AND RESULTS

We characterized the impact of DCS exposure on both germinating spores and vegetative cells of fully virulent B. anthracis by evaluating spore germination kinetics, determining the minimum inhibitory concentrations (MICs) required to affect growth of the bacteria and performing macrophage viability assays. DCS enhanced germination induced by l-alanine and also efficiently killed the newly germinated spores. Furthermore, DCS proved nontoxic to macrophages at concentrations that provided protection from the killing effects of spores. Similar tests were conducted with Bacillus thuringiensis (subspecies kurstaki and Al Hakam) to determine its potential as a possible surrogate for B. anthracis field trials. Bacillus thuringiensis spores responded in a similar manner to B. anthracis spores when exposed to DCS.

CONCLUSIONS

These results further support that DCS augments the germination response of spores in the presence of l-alanine but also reveal that DCS is bactericidal towards germinating spores.

SIGNIFICANCE AND IMPACT OF THE STUDY

DCS (or similar compounds) may be uniquely suited for use as part of decontamination strategies by augmenting the induction of spore germination and then rendering the germinated spores nonviable.

Selenium bioaccumulation in stocked fish as an indicator of fishery potential in pit lakes on reclaimed coal mines in Alberta, Canada

Pit lakes are a common reclamation strategy for open pit mines; however, there is a concern about their water quality and suitability as fish habitat because they are often contaminated by metals or metalloids. This study assessed the exposure of fish and invertebrates to selenium (Se) and other metals and metalloids in pit lakes formed by open pit coal mining in Tertiary (thermal coal) and in Cretaceous (metallurgical coal) bedrock. Juvenile hatchery rainbow trout, Oncorhynchus mykiss, and brook trout, Salvelinus fontinalis, were stocked into two thermal coal pit lakes (water Se < 2 μg/L, low water Se) and two metallurgical coal pit lakes (water Se > 15 μg/L, high water Se). Se accumulation in stocked fish and concentrations in invertebrates were characterized over a period of 2 years. In the metallurgical pits, invertebrates had higher Se concentrations and fish accumulated Se to higher levels (exceeding USEPA tissue Se guidelines) than biota in the thermal pits. Rainbow and brook trout accumulated similar concentrations of Se in their muscle and exhibited a similar relationship between whole-body and muscle Se concentrations. These results may be used by resource managers to assess compliance with whole-body tissue Se guidelines and to determine if pit lakes in coal mining areas pose a significant Se risk to wildlife or human health. The high Se exposure in metallurgical coal pits indicates that under the current mining and reclamation strategy, these lakes are not suitable for management as recreational "put and take" fisheries.

Chronic ataluren (PTC124) treatment of nonsense mutation cystic fibrosis

In a subset of patients with cystic fibrosis (CF), nonsense mutations (premature stop codons) disrupt production of full-length, functional CF transmembrane conductance regulator (CFTR). Ataluren (PTC124) allows ribosomal readthrough of premature stop codons in mRNA. We evaluated drug activity and safety in patients with nonsense mutation CF who took ataluren three times daily (morning, midday and evening) for 12 weeks at either a lower dose (4, 4 and 8 mg·kg(-1)) or higher dose (10, 10 and 20 mg·kg(-1)). The study enrolled 19 patients (10 males and nine females aged 19-57 yrs; dose: lower 12, higher seven) with a classic CF phenotype, at least one CFTR nonsense mutation allele, and an abnormal nasal total chloride transport. Both ataluren doses were similarly active, improving total chloride transport with a combined mean change of -5.4 mV (p<0.001), and on-treatment responses (at least -5 mV improvement) and hyperpolarisations (values more electrically negative than -5 mV) in 61% (p<0.001) and 56% (p = 0.002) of patients. CFTR function was greater with time and was accompanied by trends toward improvements in pulmonary function and CF-related coughing. Adverse clinical and laboratory findings were uncommon and usually mild. Chronic ataluren administration produced time-dependent improvements in CFTR activity and clinical parameters with generally good tolerability.

Abstract P2-16-08: Administration of the Novel Antiangiogenic PTC299 in Combination with Aromatase Inhibitors Is Feasible and Shows Antitumor Activity in Metastatic Breast Cancer

Background: PTC299 is an investigational new drug that suppresses tumor growth by selective post-transcriptional inhibition of tumor VEGF expression. PTC299 demonstrates antitumor activity in both hormone-receptor-positive (HR+) and-negative (HR-) breast cancer xenograft models and eliminates established tumors in aromatase-overexpressing human breast cancer xenografts when given alone or in combination with letrozole.

Methods: This study is assessing the feasibility of PTC299 administration in combination with aromatase inhibitors (AIs) in women with HR+ metastatic breast cancer and natural or induced post-menopausal levels of ovarian function. Patients already receiving or newly initiating a standard dose of an AI are coadministered 100 mg BID of oral PTC299 continuously until disease progression.

Results: To date, the study has enrolled 24 women with a median [range] age of 57 [26-82] years, ECOG PS of 0 (n=12) or 1 (n=12), to receive PTC299 together with letrozole (n=11), anastrozole (n=6), or exemestane (n=7) for a median [range] duration of ∼16 [3-36] weeks. Combination therapy has been generally well tolerated; AEs have been predominantly Grade 1-2, have usually not been PTC299-related. The most frequent AEs have been headache (25%) and hot flashes (25%). No PTC299 dose reductions or discontinuations due to AEs have occurred. Measures of PTC299 plasma exposure have shown ∼2-fold accumulation, with values reaching steady state by -21 days of treatment; trough values have exceeded those maximally active in xenograft models. Relative to baseline, therapy has been associated with on-study reductions in circulating VEGF concentrations and decreases in tumor perfusion as assessed by DCE-MRI. Antitumor activity includes 3 CRs by PET/CT, 1 PR by PET/CT, and 3 PRs by PET scan. To date, 7/24 (29%) patients have received ≥24 weeks of treatment and 10/24 (42%) patients continue on treatment.

Conclusions: Combining PTC299 100 mg BID with standard AI treatment appears feasible. Safety, exposure, pharmacodynamic, and antitumor activity observations have been encouraging. Supported by a grant award from the Department of Defense

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-16-08.

ANEMIA AND HYPOPROTEINEMIA : WEIGHT MAINTENANCE EFFECTED BY FOOD PROTEINS BUT NOT BY MIXTURES OF PURE AMINO ACIDS

Dogs with sustained anemia and hypoproteinemia due to bleeding and a continuing low protein or protein-free diet with abundant iron are used to test the value of food proteins as contrasted with mixtures of pure amino acids. The stimulus of double depletion (anemia and hypoproteinemia) drives the body to use every source of protein and all protein-building materials with the utmost conservation. Raiding of body tissue protein to produce plasma protein and hemoglobin is a factor when protein-building factors are supplied in small amounts. In this severe test (double depletion) the good food proteins in adequate amounts are able to maintain body weight, a strongly positive nitrogen balance, and produce considerable amounts of new hemoglobin and plasma protein. Casein, lactalbumin, whole egg protein, liver protein are all adequate in amounts of 150 to 250 gm. protein per week. Under comparable conditions mixtures of pure amino acids (essential for growth) do produce large amounts of new hemoglobin and plasma protein and a positive nitrogen balance but do not maintain body weight. The loss of weight is conspicuous even with large amounts of amino acids (200 to 300 gm. protein equivalent per week). Methionine, threonine, and phenylalanine are related to nitrogen conservation in growth mixtures of essential amino acids (Paper I) but when these three are given together they have little influence on the doubly depleted dog (Table 3). Some unidentified substance or compound present in certain proteins but absent in mixtures of the essential amino acids may be responsible for these differences in the response of the doubly depleted dog.

LIVER INJURY, LIVER PROTECTION, AND SULFUR METABOLISM : METHIONINE PROTECTS AGAINST CHLOROFORM LIVER INJURY EVEN WHEN GIVEN AFTER ANESTHESIA

Protein-depleted dogs are very susceptible to injurious agents-in particular, chloroform. Methionine given shortly before chloroform anesthesia will give complete protection against chloroform. Methionine (or cysteine plus choline) given 3 or 4 hours after chloroform anesthesia will give significant protection against the liver injury of chloroform anesthesia. Methionine given more than 4 hours after chloroform anesthesia gives no protection against liver injury. Choline alone given before chloroform gives no protection against liver injury. The protein-depleted dogs have livers which are deficient in both nitrogen and sulfur, but sulfur is depleted more than is the nitrogen. The N/S ratio therefore rises. Methionine or cystine feeding promptly makes up this liver sulfur deficit. Viable liver cells are necessary for this uptake of sulfur. Livers of fetuses in utero or of newborn pups tolerate a chloroform anesthesia which will cause fatal liver injury in adults. The nitrogen and sulfur values of these fetus or pup livers are within the high normal values for adults. Blood-forming cells are present in the fetus or pup livers during this period. When these blood islands are eliminated during the 3rd or 4th week of life, the liver then becomes normally susceptible to chloroform liver injury. Methionine or methionine-rich protein digests (e.g. casein) or various proteins by mouth or by vein should prove useful to protect the liver against certain types of injury and to aid in organ repair.

PLASMA PROTEIN PRODUCTION AS INFLUENCED BY PARENTERAL PROTEIN DIGESTS, VERY HIGH PROTEIN FEEDING, AND RED BLOOD CELL CATABOLISM

When blood plasma proteins are depleted by bleeding, with return of the washed red cells (plasmapheresis), it is possible to bring dogs to a steady state of hypoproteinemia and a constant level of plasma protein production if the diet nitrogen is controlled and limited. Such dogs are outwardly normal but have a lowered resistance to infection and to certain intoxications. Certain protein digests given by vein may favor good production of plasma protein, as well as nitrogen and weight equilibrium, over long periods in these standardized dogs. These digests may be equally effective when given subcutaneously or intraperitoneally and more effective orally (one dog). Certain other digests may not be well utilized. The total nitrogen of the protein digests is better retained upon oral feeding than parenteral injection. Most of the excess nitrogen excretion is not in the urea and ammonia fraction of the urine. The rate of plasma protein production may reach as high as 1 gm./kilo/day in the dog when ample protein of good quality is fed. The products of catabolism of red blood cells in vivo may add to the production of plasma protein, at least during the administration of casein digest by vein.

MAXIMAL HEMOGLOBIN AND PLASMA PROTEIN PRODUCTION UNDER THE STIMULUS OF DEPLETION

The maximal output ceiling for hemoglobin in anemia due to blood loss is about 60 gm. per week—the dog receiving a rich protein diet plus high iron intake. Ferrous and ferric salts are equally effective. Iron intravenously plus a rich protein diet may push this level up to 90 to 100 gm. per week. Evidently iron absorption is a limiting factor. Maximal output for hemoglobin plus plasma protein in doubly depleted dogs may reach 120 to 130 gm. per week and using intravenous iron may reach 140 to 160 gm. per week. Maximal output for plasma protein alone in hypoproteinemia due to plasmapheresis reaches 60 to 70 gm. per week but this is not the true ceiling. Technically we cannot remove the new plasma protein as fast as it is formed and the hypoproteinemia is not maintained in the face of a rich protein diet intake. Furthermore the evidence points to the protein circulating pool contributing to the accretion of tissue protein in such dogs with a strong positive nitrogen balance and weight gain. Maximal figures for hemoglobin production in anemia run close to 1 gm. hemoglobin per kilo per day. Maximal figures for new hemoglobin plus plasma protein production in anemia and hypoproteinemia using iron given intravenously, may reach 1.5 gm. blood protein per kilo per day. The actual maximal plasma protein production equals about 1 gm. per kilo per day but the true production ceiling cannot be reached by this technique, for reasons given above.

PLASMA PROTEIN AND HEMOGLOBIN PRODUCTION : DELETION OF INDIVIDUAL AMINO ACIDS FROM GROWTH MIXTURE OF TEN ESSENTIAL AMINO ACIDS. SIGNIFICANT CHANGES IN URINARY NITROGEN

Given healthy dogs fed abundant iron and protein-free or low protein diets with sustained anemia and hypoproteinemia, we can study the capacity of these animals to produce simultaneously new hemoglobin and plasma protein. Reserve stores of blood protein-building materials are measurably depleted and levels of 6 to 8 gm. per cent for hemoglobin and 4 to 5 gm. per cent for plasma protein can be maintained for weeks or months depending upon the intake of food proteins or amino acid mixtures. These dogs are very susceptible to infection and various poisons. Dogs tire of these diets and loss of appetite terminates many experiments. Under these conditions (double depletion) standard growth mixtures of essential amino acids are tested to show the response in blood protein output and urinary nitrogen balance. As a part of each tabulated experiment one of the essential amino acids is deleted from the complete growth mixture to compare such response with that of the whole mixture. Methionine, threonine, phenylalanine, and tryptophane when singly eliminated from the complete amino acid mixture do effect a sharp rise in urinary nitrogen. This loss of urinary nitrogen is corrected when the individual amino acid is replaced in the mixture. Histidine, lysine, and valine have a moderate influence upon urinary nitrogen balance toward nitrogen conservation. Leucine, isoleucine, and arginine have minimal or no effect upon urinary nitrogen balance when these individual amino acids are deleted from the complete growth mixture of amino acids during 3 to 4 week periods. Tryptophane and to a less extent phenylalanine and threonine when returned to the amino acid mixture are associated with a conspicuous preponderance of plasma protein output over the hemoglobin output (Table 4). Arginine, lysine, and histidine when returned to the amino acid mixture are associated with a large preponderance of hemoglobin output. Various amino acid mixtures under these conditions may give a positive urinary nitrogen balance and a liberal output of blood proteins but there is always weight loss, however we may choose to explain this loss. These experiments touch on the complex problems of parenteral nutrition, experimental and clinical.

TEN AMINO ACIDS ESSENTIAL FOR PLASMA PROTEIN PRODUCTION EFFECTIVE ORALLY OR INTRAVENOUSLY

When blood plasma proteins are depleted by bleeding with return of the washed red cells (plasmapheresis) it is possible to bring dogs to a steady state of hypoproteinemia and a constant level of plasma protein production if the diet protein intake is controlled and limited. Such dogs are outwardly normal but have a lowered resistance to infection and to certain intoxications. When the protein intake of such dogs is completely replaced by the growth mixture (Rose) of crystalline amino acids, plasma protein production is excellent, weight and nitrogen balance are maintained. This growth mixture consists of ten amino acids, threonine, valine, leucine, isoleucine, tryptophane, lysine, phenylalanine, methionine, histidine, arginine, and is as effective as most diet proteins in plasma protein production. The above amino acid mixture in aqueous solution may be given by vein with equally good plasma protein production and no apparent clinical disturbance even when given rapidly. Cystine may replace methionine in the above mixture with equally good plasma protein production for 7 to 10 days but at the expense of the body tissues, that is, with weight loss and a negative nitrogen balance. The addition of cystine to the protein-free, otherwise adequate diet may result in the production of considerable new plasma protein during a period as long as 1 week (cystine effect). This reaction may depend upon the amino acid constitution of the preceding diet protein in that it occurred following a liver feeding but did not occur after pancreas feeding. Arginine is required in the diet of the protein depleted dog for fabrication of plasma protein. It is apparently not needed for nitrogen balance for as long as 1 or 2 weeks. The omission of either threonine or valine from the growth mixture is quickly followed by a sharp decline in plasma protein formation and by a negative nitrogen balance. When histidine, arginine, and most of the lysine are omitted from the growth mixture, nitrogen balance and weight may be maintained for as long as 1 week but plasma protein production falls off markedly. The findings indicate that the growth mixture of amino acids should be a valuable addition to transfusion and infusion therapy in disease states associated with deficient nitrogen intake or tissue injury and accelerated nitrogen loss, including shock, burns, and major operative procedures.

HEMOGLOBIN AND PLASMA PROTEIN : SIMULTANEOUS PRODUCTION DURING CONTINUED BLEEDING AS INFLUENCED BY AMINO ACIDS, PLASMA, HEMOGLOBIN, AND DIGESTS OF SERUM, HEMOGLOBIN, AND CASEIN

Given healthy dogs, fed abundant iron and protein-free or low protein diets, with sustained anemia due to bleeding, we can study the capacity of these animals to produce simultaneously new hemoglobin and plasma protein. The reserve stores of blood protein producing materials in this way are very largely depleted, and levels of 6 to 8 gm. per cent for hemoglobin and 4 to 5 gm. per cent for plasma protein can be maintained for considerable periods of time. These dogs are very susceptible to infection and to injury by many poisons. Under such conditions, these anemic and hypoproteinemic dogs will use very efficiently a variety of digests (serum, hemoglobin, and casein) and the growth mixture (Rose) of pure amino acids. Nitrogen balance is maintained and considerable new blood proteins are produced. Dog plasma by vein is used freely in these doubly depleted dogs to make new hemoglobin in abundance (Table 1). Serum digests by vein are well utilized to make new hemoglobin and plasma protein in the same dogs (Table 1). Serum digests by mouth are effectively used to make new blood proteins (Table 5). Dog or sheep hemoglobin given in large amounts intraperitoneally are remarkably well utilized to form hemoglobin and plasma protein (Table 6). It must be obvious that the globin of the hemoglobin is saved in these protein-depleted dogs and used to make large amounts of hemoglobin and plasma protein. Hemoglobin digests are also well utilized whether given by mouth (Table 7) or by vein (Table 8) and liberal amounts of plasma protein are manufactured from digests presumably ideally suited for hemoglobin production. Casein digests are well used (Table 8) and form as much new plasma protein as any material tested-even serum digests. Amino acid mixtures are of especial interest. The growth mixture of 10 amino acids (Rose) is well utilized by mouth or by vein and favors new hemoglobin production more than any material tested (Table 2). Cystine replacing methionine in the amino acid mixture increases the plasma protein-hemoglobin output ratio, that is it favors plasma protein production. Digests of various sorts and amino acid mixtures or combinations of digests and amino acid mixtures can be used rapidly and effectively to build new hemoglobin or plasma protein, to maintain nitrogen equilibrium, and to replete reserve protein stores. These experiments point to clinical problems. The unexplained preference given to hemoglobin production in these hypoproteinemic dogs is observed under all conditions, even when whole plasma or serum digests are given by vein. In general, 2 to 4 gm. of hemoglobin are formed for every gram of plasma protein. This all adds up to a remarkable fluidity in the use of plasma protein or hemoglobin which can contribute directly to the body protein pool from which are evolved, without waste of nitrogen, the needed proteins, whether hemoglobin, plasma protein, or tissue proteins.

CASEIN DIGESTS PARENTERALLY UTILIZED TO FORM BLOOD PLASMA PROTEIN

When blood plasma proteins are depleted by bleeding with return of the washed red cells (plasmapheresis) it is possible to bring dogs to a steady state of hypoproteinemia and a uniform plasma protein production on a basal diet limited in protein. Such dogs are clinically normal but have a lowered resistance to infection and certain intoxications. Casein digests given by vein or subcutaneously to such plasma depleted dogs are effective in promoting abundant new plasma protein production. Casein digest L by vein is equivalent to whole liver of like protein equivalence by mouth. The ratio of new plasma protein production to protein intake is 20 to 25 per cent in both instances. Casein digest L by vein gives the same response in plasma protein output as the same digest by mouth. Protein digest X by vein requires addition of tryptophane and cysteine to be effective in plasma protein production. The added cysteine sulfur is more than 95 per cent retained by the dog. The speed of digest injection has no effect on its utilization, within the range tested. Casein digest L given by vein to non-depleted dogs is less well utilized than in dogs depleted of plasma protein.

RAIDING OF BODY TISSUE PROTEIN TO FORM PLASMA PROTEIN AND HEMOGLOBIN : WHAT IS PREMORTAL RISE OF URINARY NITROGEN?

Dogs with sustained anemia and hypoproteinemia due to bleeding and a continuing low protein or protein-free diet with abundant iron will continue to produce much new hemoglobin and plasma protein for many weeks. The stimulus of double depletion (anemia and hypoproteinemia) leads to raiding of body and tissue protein to fill the demand for new hemoglobin and plasma protein. The blood proteins in these experiments take priority over the organ and tissue proteins. This is another illustration of the "ebb and flow" or dynamic equilibrium between organ or tissue protein and blood proteins. The average dog cannot tolerate this drain of double depletion for more than 7 to 11 weeks and during this time may lose 30 to 40 per cent of body weight. Some dogs are much more resistant to this raiding than others. Some dogs show a high blood protein output during every week up to the danger point. With the largest blood protein output one usually observes the most rapid weight loss. For every kilogram of weight loss we observe 50 to 140 gm. blood protein output. The weekly blood protein production ranges from 40 to 66 gm. These experiments make heavy demands on the body protein and we expected to record a "premortal rise" in urinary nitrogen. No such observations are noted, rather a most frugal use of all protein and minimum figures for urinary nitrogen. We suspect that "premortal rise" in many experiments means a terminal infection with the related catabolism of tissue protein and high urinary nitrogen.

HEMOGLOBIN AND PLASMA PROTEIN : THEIR RELATION TO INTERNAL BODY PROTEIN METABOLISM

Hemoglobin (presumably its essential protein globin), given intraperitoneally to a protein-fasting dog, will be used effectively to supply the protein requirements of the body. Nitrogen balance may thus be maintained for 20 days under favorable conditions. New hemoglobin and plasma protein will be formed related to hemoglobin injections in depleted dogs where there is urgent need for these proteins (anemia and hypoproteinemia). Obviously this calls for supplementary amino acids which in globin are low and we assume these amino acids must be contributed from body protein stores. Plasma proteins (in plasma) tested in the same manner are completely utilized with no loss of nitrogen, positive nitrogen balance, weight balance, and no change in the albumin-globulin ratios. Hemoglobin (globin) is less effectively utilized as compared with plasma protein given parenterally and there is some increase in urinary nitrogen above control periods. The albumin-globulin ratio may be somewhat modified by hemoglobin injections intraperitoneally. Hemoglobin (globin) digests contribute effectively to body maintenance of nitrogen equilibrium. These digests are about as effective as whole hemoglobin in maintaining nitrogen balance but cause a rise in undetermined nitrogen not seen when hemoglobin alone is given intraperitoneally. Pigment radicles derived from hemoglobin given intraperitoneally are thrown away and appear as surplus bile pigment even when there is urgent need for all available nitrogenous material—given protein fasting, anemia, and hypoproteinemia in a bile fistula dog. The body evidently prefers to make rather than conserve the pyrrol aggregate (pigment radicle). We assume that the injected hemoglobin (globin) or hemoglobin digests contribute to the body protein pool and from this pool various proteins emerge to supply protein requirements of tissue or organ cells or to produce new hemoglobin or plasma protein if needed. We have no explanation as to what determines the pattern of this protein flow but new hemoglobin is very high on the priority list.

THE EFFECT OF dl-METHIONINE, l-CYSTINE, AND dl-ISOLEUCINE ON THE UTILIZATION OF PARENTERALLY ADMINISTERED DOG HEMOGLOBIN : A SUGGESTION FOR DESIGNING THE COMPOSITION OF THE "IDEAL" PROTEIN DIGEST

1. Further observations on the utilization of parenterally administered dog hemoglobin show that oral supplements of dl-methionine and l-cystine improve the efficiency of utilization of hemoglobin N, while a fed supplement of dl-isoleucine alone is without effect. 2. When N-isoleucine is added to a fed supplement of methionine or methionine and cystine, the utilization of parenterally given hemoglobin N is even better than with the sulfur-containing amino acids alone. 3. A suggested approach to the problem of designing the quantitatively "ideal" amino acid mixture lies in the definition of what may be called total organism-amino acid patterns of rat, dog, man, etc. These may vary considerably not only at different developmental stages in a given species, but also certainly from one species to another. 4. Further attempts to detect globin in the peripheral circulation have pointed to the need for a highly specific procedure such as that an immunologic method may offer. 5. Reduced hemin in dog plasma migrates with α₁-globulin and albumin in veronal buffer at pH 8.5 and the colored zones give strong hemochromogen absorption bands.

PERITONEAL ABSORPTION : RED CELLS LABELED BY RADIO-IRON HEMOGLOBIN MOVE PROMPTLY FROM PERITONEAL CAVITY INTO THE CIRCULATION

The absorption of red cells from the normal peritoneum of the dog can be demonstrated by means of red cells labeled with radio-iron incorporated in the hemoglobin of these red cells. Absorption in normal dogs runs from 20 to 100 per cent of the amount given within 24 hours. Dogs rendered anemic by bleeding absorb red cells a little less rapidly—ranging from 5 to 80 per cent of the injected red cells. Doubly depleted dogs (anemic and hypoproteinemic) absorb even less in the three experiments recorded. This peritoneal absorption varies widely in different dogs and even in the same dog at different times. We do not know the factors responsible for these variations but there is no question about active peritoneal absorption. The intact red cells pass readily from the peritoneal cavity into lymph spaces in diaphragm and other areas of the peritoneum. The red cells move along the lymphatics and through the lymph glands with little or no phagocytosis and eventually into the large veins through the thoracic ducts.

GELATIN-ITS USEFULNESS AND TOXICITY : BLOOD PROTEIN PRODUCTION IMPAIRED BY CONTINUED GELATIN BY VEIN

Gelatin given by vein to doubly depleted dogs (anemic and hypoproteinemic) gives no immediate toxic response, no anaphylactoid reactions, and may contribute something to the building of new hemoglobin and plasma protein. Gelatin given by vein during 1 to 2 weeks (total 3 to 17 gm. per kilo) usually causes serious disturbances—inhibition of blood protein production, signs of intoxication, much weight loss, and even death. Gelatin given by vein for 2 to 3 days (total 1 to 3 gm. per kilo) may not cause any recognizable abnormalities, but dogs vary greatly in their response to gelatin by vein. Some dogs may tolerate a total of 7 gm. per kilo without significant disturbance and other dogs may be seriously intoxicated by 2 to 3 gm. per kilo. No one can predict which animal will be least tolerant. Some experiments with gelatin by vein for 2 to 3 days (total gelatin 1 to 2 gm. per kilo) given with and followed by amino acids or casein digests do show absence of intoxication and ample production of new hemoglobin and plasma protein during the weeks following the injection of gelatin. This may suggest possible usefulness of gelatin with amino acids or casein digests in acute emergencies (shock, hemorrhage). These doubly depleted dogs are very susceptible to various injurious agents as compared to normal dogs. They may serve as sensitive testing machines for evaluating plasma substitutes. Where the gelatin by vein inflicts its damage is not clear and there is little if any significant histological evidence but the disturbance of blood protein production implicates the liver. Gelatin of smaller molecular weight (degraded by autoclaving) is no less toxic than the standard gelatin. Gelatin by mouth may contribute to but cannot alone support the production of new hemoglobin and plasma protein. Gelatin by vein has definite limitations in dogs and, by implication, when used in human cases the amount given should be very carefully watched.

Physiological stress response in white suckers from agricultural drain waters containing pesticides and selenium

To assess the effect of agriculture drain water, a complex mixture containing pesticides and selenium (Se), on the physiological stress response, white suckers were collected from irrigation return flows in the summer and the fall and subjected to a stress challenge. Water (0.40-26.71microg/L) and muscle Se (0.37-1.52microg/g ww) levels were elevated at two sites and plasma acetylcholinesterase (AChE) activity (a marker of pesticide exposure) was lower in the fall (5.97+/-0.45micromol/min/mL) than the summer (10.73+/-0.73micromol/min/mL). Fish raised plasma cortisol levels in response to the stress challenge 11.8 times above basal levels (12.8+/-4.9ng/mL). Multivariate statistics linked Se exposure to elevated plasma glucose levels, and pesticide exposure to elevated liver glycogen levels generating hypotheses for further testing. This study showed that white suckers accumulated Se from agricultural drain water and the complex mixtures present in the drain water influenced the physiological stress response.

Effects of acute and subchronic exposures to waterborne selenite on the physiological stress response and oxidative stress indicators in juvenile rainbow trout

Selenium (Se) is an essential element that may bioaccumulate to toxic levels. In fish, the major toxicity symptom is larval teratogenic deformities, but little is known about the effect of Se on other systems such as the physiological stress response and oxidative stress. To test the hypothesis that Se is a chemical stressor that causes toxicity through oxidative stress, juvenile rainbow trout were exposed to waterborne sodium selenite, and physiological stress response and stress-related parameters (plasma cortisol, glucose, T3 and T4, gill Na+/K+-ATPase, the ability of the head kidney to secrete cortisol, and condition factor) and hepatic oxidative stress indicators (reduced glutathione, glutathione peroxidase, and lipid peroxidation) were measured after 96 h (acute exposure to 0-2.67 mg/L Se) and 30 days (sub-chronic exposure to 0-0.16 mg/L). Acute exposure to waterborne sodium selenite significantly increased plasma cortisol levels (control=0.01+/-0.0 ng/mL, and 2.52 mg/L Se=73.5+/-22 ng/mL) and plasma glucose levels (control=0.75+/-0.1 mg/mL, and 3.60 mg/L Se=1.64+/-0.2 mg/mL), but gill Na+/K+-ATPase activities, plasma T3 and T4 levels, and condition factor were unchanged. The 96 h acute selenite exposure decreased hepatic reduced glutathione levels (control=18.4+/-1.5 micromol/mg protein, and 3.60 mg/L Se=12.4+/-1.1 micromol/mg protein). Lipid peroxidation levels (0.03-0.08 U/mg protein) and glutathione peroxidase (3.7-6.0 mU/mg protein) activities significantly varied with treatment. The 30 days sub-chronic exposure increased plasma cortisol, T3, and T4, but there was no effect on plasma glucose levels, gill Na+/K+-ATPase activity, the ability to secrete cortisol, and condition factor. The 30 days sub-chronic exposure to selenite did not alter antioxidant activities or lipid peroxidation levels. These experiments show, for the first time, that exposure to waterborne selenite up to 0.1mg/L, activates the physiological stress response in fish but does not impair cortisol secretion after 30 days. The decrease in reduced glutathione in juvenile rainbow trout subjected to the acute sodium selenite exposure suggests that oxidative stress may play an important role in the effects of Se in fish.

Missing quasiparticles and the chemical potential puzzle in the doping evolution of the cuprate superconductors

The evolution of Ca2-xNaxCuO2Cl2 from Mott insulator to superconductor was studied using angle-resolved photoemission spectroscopy. By measuring both the excitations near the Fermi energy as well as nonbonding states, we tracked the doping dependence of the electronic structure and the chemical potential with unprecedented precision. Our work reveals failures in the standard weakly interacting quasiparticle scenario, including the broad line shapes of the insulator and the apparently paradoxical shift of the chemical potential within the Mott gap. To resolve this, we develop a model where the quasiparticle is vanishingly small at half filling and grows upon doping, allowing us to unify properties such as the dispersion and Fermi wave vector with the chemical potential.

The effect of changing from secondary to primary safety belt enforcement on police harassment

The purpose of the study was to investigate whether changing Michigan's safety belt law from secondary to primary (standard) enforcement resulted in police harassment. The study investigated safety-belt-enforcement-related harassment by considering three measures: citizen complaints arising from enforcement of the safety belt law; citation over-representation, that is, a statistical determination of whether certain groups received more citations than would be expected based upon their presence in the driving population and their rate of violating the safety belt use law; and self-reported harassment among the population of people who receive safety belt citations. Safety-belt-related harassment complaints were very uncommon both before and after primary enforcement. Implementation of primary enforcement did not lead to an increase in citation over-representation, and, therefore, safety-belt-related harassment by sex, race, or age. The vast majority of people receiving safety belt citations reported officer behavior as professional and did not feel that they were singled out for their citation. However, a sizeable minority of Blacks and young people report perceptions of safety-belt-related harassment. Results suggest that states with secondary enforcement should continue their efforts to change to primary enforcement, but should also make a strong effort to educate both law enforcement and the public about the harassment issue.

A phase I study of sequential irinotecan and 5-fluorouracil/leucovorin

BACKGROUND

Irinotecan (CPT-11) and 5-fluorouracil (5-FU)/leucovorin are active agents in colorectal cancer. A sequence-dependent synergism of SN-38 followed by 5-FU/leucovorin in vitro led us to conduct a phase I trial of CPT-11 followed by 5-FU/leucovorin to determine the maximum tolerated dose (MTD) and toxicities of this regimen and to obtain preliminary indications of its activity in patients with advanced solid tumors.

PATIENTS AND METHODS

Fifty-six patients were enrolled in sequential cohorts to receive escalating doses of CPT-11 (90 min infusion) on day 1, followed by leucovorin 20 mg/m(2) (intravenous push) and 5-FU (90 min infusion) on days 2-5 of each 21-day cycle.

RESULTS

A total of 347 treatment cycles (median 4, range 1-25) were administered. Dose-limiting toxicities were diarrhea, neutropenia and fatigue. Nine patients with colorectal cancer and one with gastric cancer had partial or minor responses. Eight of the 10 had prior chemotherapy.

CONCLUSIONS

CPT-11 and 5-FU/leucovorin, as constituents of this novel mechanism-based schedule, have promising activity in patients who have received prior chemotherapy. The recommended phase II/III starting doses are CPT-11 275 mg/m(2) over 90 min on day 1, and 5-FU 400 mg/m(2) plus leucovorin 20 mg/m(2) on days 2-5 every 21 days. This combination can be administered safely to this schedule if there is strict adherence to the 90 min infusion time for both CPT-11 and 5-FU.

Phase I dose-finding and pharmacokinetic trial of irinotecan (CPT-11) administered every two weeks

OBJECTIVES

This trial was performed to determine the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), and pharmacokinetic profile of irinotecan (CPT-11) when administered on a once-every-2-week schedule.

PATIENTS AND METHODS

CPT-11 was administered to successive cohorts of patients at progressively increasing starting doses ranging from 125 to 350 mg/m2. The MTD and DLTs were determined both for CPT-11 alone and for CPT-11 followed by filgrastim (G-CSF). Plasma samples were obtained during the first 24 hours after initial dosing to determine the total concentrations (lactone + carboxylate forms) of CPT-11; of the active metabolite SN-38; and of SN-38 glucuronide (SN-38G).

RESULTS

Neutropenic fever was the DLT for CPT-11 at the 300 mg/m2 dose level. When G-CSF was added, dose escalation beyond 350 mg/m2 could not be achieved due to grade 2-3 toxicities that prevented on-time retreatment with CPT-11. Severe, late diarrhea was uncommon on this schedule. Peak plasma concentrations of SN-38 and SN-38G were approximately 2.5% and 4.2% of the corresponding peak plasma concentration for CPT-II, respectively The harmonic mean terminal half-lives for CPT-11, SN-38, and SN-38G were 7.1 hours, 13.4 hours, and 12.7 hours, respectively. No predictive correlation was observed between CPT-11 or SN-38 peak concentration or AUC and first-cycle diarrhea, neutropenia, nausea, or vomiting. Across the range of doses studied, mean CPT-11 clearance was 14.0 +/- 4.0 l/h/m2 and volume of distribution was 146 +/- 45.9 l/m2.

CONCLUSIONS

When administered every two weeks, the recommended phase II starting dose of CPT-11 is 250 mg/m2 when given alone and 300 mg/m2 when supported by G-CSF. This every-two-week regimen offers a tolerable and active alternative to weekly or every-three-week single-agent CPT-11 therapy.

A phase II study of irinotecan with 5-fluorouracil and leucovorin in patients with previously untreated gastric adenocarcinoma

BACKGROUND

A phase II study testing the safety and efficacy of irinotecan (CPT-11). 5-fluorouracil (5-FU), and leucovorin (LCV) was conducted in patients with advanced gastric adenocarcinomas.

PATIENTS AND METHODS

Patients with metastatic or recurrent adenocarcinoma of the gastroesophageal junction (GEJ) or stomach were entered onto this study. Previous chemotherapy for metastatic disease was not allowed. Treatment consisted of repeated 6-week cycles comprising CPT-11 125 mg/m2 intravenously (i.v.) followed immediately by LCV 20 mg/m2 i.v. and 5-FU 500 mg/m2 i.v., all given weekly for four weeks followed by a two-week rest.

RESULTS

Thirty-eight patients were enrolled and 36 eligible patients received protocol therapy. Grade 3-5 toxicities consisted primarily of neutropenia (36%) and diarrhea (28%). Neutropenic infection was observed in 14% of patients, with 3 (8%) dying of neutropenic sepsis. The overall response rate was 22% (95% confidence interval [CI] 8.5% to 35.5%). Median survival was 7.6 months, and median time to progression was 4.4 months.

CONCLUSION

This weekly regimen of CPT-11 with bolus 5-FU/LCV is active in patients with advanced adenocarcinomas of the stomach or gastroesophageal junction. While rates of grade 3-4 neutropenia and diarrhea were similar to those observed historically in patients receiving this regimen for colorectal cancer, neutropenic fever/sepsis appeared to be more frequent, and dose modifications were substantial. Future trials of this combination in patients with gastric cancer should decrease the absolute starting drug doses and/ or employ altered scheduling that better accommodates the pattern of toxicity.

Parity-forbidden excitations of Sr(2)CuO(2)Cl(2) revealed by optical third-harmonic spectroscopy

We present the first study of nonlinear optical third-harmonic generation (THG) in the strongly correlated charge-transfer insulator Sr(2)CuO(2)Cl(2). For fundamental excitation in the near infrared, the THG spectrum reveals a strongly resonant response for photon energies near 0.7 eV. Polarization analysis reveals this novel resonance to be only partially accounted for by three-photon excitation to the optical charge-transfer exciton, and indicates that an even-parity state at 2 eV, with a(1g) symmetry, participates in the third-harmonic susceptibility.

Analysis of speech characteristics in children with velocardiofacial syndrome (VCFS) and children with phenotypic overlap without VCFS

OBJECTIVE

To address two questions of theoretical importance regarding the profile and course of communication impairment associated with velocardiofacial syndrome (VCFS): (1) do speech characteristics of children with VCFS differ from a group of children with some of the phenotypic characteristics of VCFS who do not have the syndrome, and (2) do younger children with VCFS demonstrate speech patterns that differ from older children with VCFS?

DESIGN

Prospective, cross-sectional study comparing two groups of children at two age levels.

PATIENTS

Thirteen children with VCFS and eight children with some of the phenotypic features of VCFS who did not have the syndrome. Children ranged in age from 3 to 10 years.

MAIN OUTCOME MEASURE

(1) Broad phonetic transcription of speech yielding measures of number of consonant types, Percent Consonant Correct, and percentage of glottal stops used; and (2) composite ratings of velopharyngeal function made from perceptual, aerodynamic, and endoscopic evaluations.

RESULTS

Younger children with VCFS demonstrated greater speech impairment than older children with VCFS or the children without VCFS, such as smaller consonant inventories, greater number of developmental errors, greater severity of articulation disorder, and higher frequency of glottal stop use. The relationship between ratings of velopharyngeal function and the speech variables analyzed was not straightforward.

CONCLUSIONS

Some young children with VCFS demonstrated speech impairment that is qualitatively and quantitatively different from older children with VCFS or children without VCFS. This finding supports the hypothesis that some children with VCFS demonstrate a profile of speech production that is different from normal but also may be specific to the syndrome.

Irinotecan (CPT-11) in Triplet Combinations in Patients with Advanced Non–Small-Cell Lung Cancer: A Review and Report of a Phase I/II Trial

The objectives of this phase I/II trial were to determine the maximum tolerated dose, toxicities, and the dose suitable for phase II/III trials of irinotecan (CPT-11) combined with paclitaxel and carboplatin in patients with advanced non small-cell lung cancer (NSCLC). Seventy-three patients with stage IIIB/IV NSCLC were enrolled in this multicenter, phase I/II study. The initial regimen was paclitaxel 225 mg/m2 over 3 hours, followed by carboplatin at an area under the curve (AUC) of 6 over 30 minutes on day 1 and CPT-11 starting at 40 mg/m2 over 90 minutes on days 1 and 8, every 3 weeks. Dose-limiting toxicity occurred in three of the original seven patients. The regimen was amended with doses reduced to paclitaxel 175 mg/m2 over 3 hours, carboplatin AUC = 5, and CPT-11 at 40 mg/m2, all on day 1 every 3 weeks. Dose escalation of CPT-11 proceeded to 80 mg/m2 and 125 mg/m2 before dose-limiting toxicities were experienced. Subsequent patients received an intermediate CPT-11 dose of 100 mg/m2. Doses suitable for phase II study were determined to be paclitaxel 175 mg/m2 over 3 hours, carboplatin AUC = 5, and CPT-11 100 mg/m2. The pri-mary first-cycle dose-limiting toxicities were neutropenia and diarrhea. The most common grade 3/4 toxicity observed during all cycles was neutropenia. On the phase I portion of the study, objective tumor response was observed in 39% (12 of 31, 95% confidence interval: 22%-58%). The median time to tumor progression was 6.8 months, median survival was 11.0 months, and 1-year survival probability was 0.46. These data were confirmed in the phase II portion with a 30% objective response rate, median time to progression of 5.6 months, median survival of 12.5 months, and a 1-year survival probability of 0.50. In conclusion, CPT-11 100 mg/m2, paclitaxel 175 mg/m2, and carboplatin AUC = 5 given every 3 weeks can be safely administered in patients with advanced NSCLC. Neutropenia and diarrhea are the dose-limiting toxicities. The combination shows appreciable activity, and survival data are favorable, warranting further study of this regimen. A review of other irinotecan-containing triplet combinations is presented.

Irinotecan plus fluorouracil/leucovorin for metastatic colorectal cancer: a new survival standard

BACKGROUND

Irinotecan is a topoisomerase I inhibitor that prolongs survival in patients with colorectal cancer refractory to fluorouracil (5-FU) and leucovorin (LV). This demonstrated activity of irinotecan as effective second-line therapy for colorectal cancer led to evaluation of combination irinotecan/5-FU/LV as first-line therapy for patients with metastatic disease. The results of two prospective phase III randomized, controlled, multicenter, multinational clinical trials in patients with previously untreated metastatic colorectal cancer served as the basis for U.S. and European approval of irinotecan/5-FU/LV for this indication. An overview of the findings of these two pivotal studies provides insights regarding the application of this new combination in clinical practice.

METHODS

Patients were randomly assigned to receive 5-FU/LV, either alone, or with concurrent irinotecan. The study conducted primarily in North America (study 1), employed bolus 5-FU/LV schedules, while the study performed primarily in Europe (study 2), employed infusional 5-FU/LV regimens. Major endpoints included tumor response rate, time to tumor progression (TTP), overall survival, quality of life, and safety.

RESULTS

In study 1, the respective confirmed response rates for irinotecan/5-FU/LV versus 5-FU/LV were 39% and 21% (p <.001); median TTPs were 7.0 months and 4.3 months, respectively (p =.004). In study 2, response rates for irinotecan/5-FU/LV versus 5-FU/LV alone were 35% and 22% (p =.005); median TTPs were 6.7 months and 4.4 months, respectively (p <.001). Survival time increased significantly with irinotecan/5-FU/LV versus 5-FU/LV alone in both studies (study 1: median 14.8 months versus 12.6 months, p =.042; study 2: median 17.4 months versus 14.1 months, p =.032). The combined analysis of the data from the two studies showed median survivals of 15.9 months versus 13.3 months, favoring the irinotecan-containing combinations (stratified-by-study p =.003). Patients in study 1 had a 36% lower risk of tumor progression and a 20% lower risk of death with the irinotecan combination than with 5-FU/LV alone; comparable risk reduction values in study 2 were 42% and 23%. While grade 3 diarrhea and vomiting were more common with irinotecan/5-FU/LV, grade 4 neutropenia, neutropenic fever, and mucositis were less common with irinotecan/5-FU/LV than with the Mayo Clinic 5-FU/LV regimen.

CONCLUSION

The combination of irinotecan/5-FU/LV is superior to 5-FU/LV alone as first-line therapy for patients with metastatic colorectal cancer, offering consistently improved tumor control and prolonged survival. Irinotecan-based combination therapy sets a new survival standard for the treatment of this life-threatening disease.

Over-expression of the INO2 regulatory gene alters regulation of an INO1-lacZ reporter gene but does not affect regulation of INO1 expression

The yeast INO2 gene encodes a transcriptional activator. Inositol and choline repress transcription of the INO2 gene, and its target genes. That is, INO2 transcription is auto-regulated. This observation prompted two separate investigations to determine if regulation of INO2 is required for regulation of its target genes. One study, using northern blot hybridization, showed that constitutive INO2 transcription did not affect regulation of the INO1 gene, while another study revealed that it severely dampened regulation of an INO1-lacZ gene. By repeating both assays from a single yeast strain we demonstrate that this disparity is due to the different reporter systems.

A prospective randomized phase II trial of GM-CSF priming to prevent topotecan-induced neutropenia in chemotherapy-naive patients with malignant melanoma or renal cell carcinoma

We conducted a phase II randomized trial of recombinant granculocyte-macrophage colony-stimulating factor (GM-CSF) administered before topotecan chemotherapy to determine whether it could prevent myelosuppression and to determine the antitumor activity of this topoisomerase I inhibitor in 53 patients with metastatic malignant melanoma and renal cell cancer. All patients received GM-CSF after topotecan at a dose of 250 microg/m(2) daily for at least 8 days. Patients randomly assigned to receive GM-CSF priming were treated with GM-CSF at 250 microg/m(2) twice daily for 5 days before treatment. Twenty-five patients were randomly assigned to receive GM-CSF priming and 28 to receive topotecan without priming. The primary analysis was restricted to the protective effects seen during the first cycle of therapy. Grade 4 neutropenia occurred in 8 of 23 patients (35%) and grade 3 neutropenia in 5 of 23 patients (22%) randomized to GM-CSF priming, whereas 18 of 26 (69%) and 5 of 26 (19%) patients experienced grade 4 or 3 neutropenia, respectively, without GM-CSF priming (P =.0074). The mean duration of neutropenia was reduced by GM-CSF priming: grade 3 neutropenia from 5.2 +/- 0.7 to 2.8 +/- 0.7 days (P =.0232) and grade 4 neutropenia from 2.7 +/- 0.6 to 1.1 +/- 0.4 days (P = 0.0332). The protective effects of GM-CSF extended to the second cycle of treatment. The incidence of febrile neutropenia was also reduced. Chemotherapy-induced anemia and thrombocytopenia were similar in both groups. One partial response was seen in a patient with melanoma, and one patient with renal cell cancer had complete regression of pulmonary metastases and was rendered disease-free by nephrectomy. (Blood. 2001;97:1942-1946)

Phase I trial of the combination of irinotecan, paclitaxel, and carboplatin in patients with advanced non-small-cell lung cancer

PURPOSE

To determine the maximum-tolerated dose, toxicities, and dose suitable for phase II/III trials of irinotecan (CPT-11) combined with paclitaxel and carboplatin in patients with advanced non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients with stage IIIB/IV NSCLC were enrolled to this multicenter, phase I study. The initial regimen was paclitaxel 225 mg/m(2)/3 h, followed by carboplatin area under the curve (AUC) 6 over 30 minutes on day 1, and CPT-11 starting at 40 mg/m(2) over 90 minutes, days 1 and 8, every 3 weeks. Dose-limiting toxicity occurred in three of seven patients. The regimen was amended, with doses reduced to paclitaxel 175 mg/m(2)/3 h, carboplatin AUC 5 and CPT-11 at 40 mg/m(2), all on day 1 every 3 weeks. Dose escalation of CPT-11 proceeded to 80 mg/m(2) then 125 mg/m(2) before dose-limiting toxicities were experienced. Subsequent patients received an intermediate CPT-11 dose of 100 mg/m(2).

RESULTS

Thirty-three patients were enrolled; 32 patients were assessable for safety, and 31 were assessable for tumor response. The primary first-cycle dose-limiting toxicities were neutropenia and diarrhea. The most common grade 3/4 toxicity observed during all cycles was neutropenia (16 patients [50%], with six [19%] developing neutropenic fever). Objective tumor response was observed in 39% (12/31, 95% confidence interval, 22% to 58%). The median time to tumor progression was 6.8 months, median survival 11.0 months, and 1-year survival probability 0.46.

CONCLUSION

CPT-11 100 mg/m(2), paclitaxel 175 mg/m(2), and carboplatin AUC 5 given every 3 weeks can be safely administered in patients with advanced NSCLC. Neutropenia and diarrhea are the dose-limiting toxicities. The combination shows appreciable activity, and survival data are favorable.

Irinotecan plus fluorouracil and leucovorin for metastatic colorectal cancer. Irinotecan Study Group

BACKGROUND

The combination of fluorouracil and leucovorin has until recently been standard therapy for metastatic colorectal cancer. Irinotecan prolongs survival in patients with colorectal cancer that is refractory to treatment with fluorouracil and leucovorin. In a multicenter trial, we compared a combination of irinotecan, fluorouracil and leucovorin with bolus doses of fluorouracil and leucovorin as first-line therapy for metastatic colorectal cancer. A third group of patients received irinotecan alone.

METHODS

Patients were randomly assigned to receive irinotecan (125 mg per square meter of body-surface area intravenously), fluorouracil (500 mg per square meter as an intravenous bolus), and leucovorin (20 mg per square meter as an intravenous bolus) weekly for four weeks every six weeks; fluorouracil (425 mg per square meter as an intravenous bolus) and leucovorin (20 mg per square meter as an intravenous bolus) daily for five consecutive days every four weeks; or irinotecan alone (125 mg per square meter intravenously) weekly for four weeks every six weeks. End points included progression-free survival and overall survival.

RESULTS

Of 683 patients, 231 were assigned to receive irinotecan, fluorouracil, and leucovorin; 226 to receive fluorouracil and leucovorin; and 226 to receive irinotecan alone. In an intention-to-treat analysis, as compared with treatment with fluorouracil and leucovorin, treatment with irinotecan, fluorouracil, and leucovorin resulted in significantly longer progression-free survival (median, 7.0 vs. 4.3 months; P=0.004), a higher rate of confirmed response (39 percent vs. 21 percent, P<0.001), and longer overall survival (median, 14.8 vs. 12.6 months; P=0.04). Results for irinotecan alone were similar to those for fluorouracil and leucovorin. Grade 3 (severe) diarrhea was more common during treatment with irinotecan, fluorouracil, and leucovorin than during treatment with fluorouracil and leucovorin, but the incidence of grade 4 (life-threatening) diarrhea was similar in the two groups (<8 percent). Grade 3 or 4 mucositis, grade 4 neutropenia, and neutropenic fever were less frequent during treatment with irinotecan, fluorouracil, and leucovorin. Adding irinotecan to the regimen of fluorouracil and leucovorin did not compromise the quality of life.

CONCLUSIONS

Weekly treatment with irinotecan plus fluorouracil and leucovorin is superior to a widely used regimen of fluorouracil and leucovorin for metastatic colorectal cancer in terms of progression-free survival and overall survival.

Exemestane improves survival in metastatic breast cancer: results of a phase III randomized study

We compared the efficacy and safety of the oral aromatase inactivator exemestane (EXE) with megestrol acetate (MA) in women with metastatic breast cancer. This phase III randomized, double-blind, multicenter study was conducted in 769 postmenopausal women who had experienced tamoxifen failure. Treatment arms consisted of EXE 25 mg once daily (n=366) or MA 40 mg four times daily (160 mg daily; n=403). Peer-reviewed, intent-to-treat analyses demonstrated that EXE induced a trend toward higher rates of complete response (CR)+partial response (PR) (15.0% vs. 12.4%) and of CR+PR+stable disease (SD)=24 weeks (37.4% vs. 34.6%), but differences were not statistically significant. Statistically significant differences favoring EXE were seen in median duration of CR+PR+SD=24 weeks (60.1 vs. 49.1 weeks; P=0.025), time to tumor progression (20.3 vs. 16.6 weeks; P=0.037), time to treatment failure (16.3 vs. 15.7 weeks; P=0.042), and overall survival (not reached vs. 123.4 weeks; P=0.039). Both treatments were well tolerated, but MA was associated with more grade 3 or 4 weight gain (8% vs. 17%, P=0.001); the pain score was sim-ilar in both groups. There was a trend toward superiority in treatment-related signs and symptoms (TRSS) with EXE. There was greater improvement in the pain score and TRSS in patients achieving an objective response with EXE vs. MA. Quality of life improved or was similar for EXE in most domains. Exemestane offers an important new treatment option for postmenopausal women with hormone-responsive breast cancer.

Univariate genetic analyses of epilepsy and seizures in a population-based twin study: the Virginia Twin Registry

The purpose of this study was to examine the roles of genetic and environmental factors in the etiology of epilepsy and seizures in twins ascertained from the Virginia Twin Registry. Health history information on twins was collected by questionnaire. Concordance rates were calculated and used to estimate degree of concordance for seizure types in monozygotic (MZ) and dizygotic (DZ) twin pairs. Univariate twin analyses were performed for each epilepsy and seizure type to determine models which best explained observed variation. Health history information concerning epilepsy and febrile seizure occurrences was provided by members of 8,655 twin pairs; 6,684 of these supplied additional information reporting absence, complex partial, tonic-clonic, and unspecified seizures. Models including additive genetic and unique environmental factors best explained febrile seizures, epilepsy, complex partial seizures, and unspecified seizures. For complex partial seizures, however, the contributions of genetic and environmental effects did not vary across gender. These results show that, under univariate analysis methods, genetic factors played an important role in the expression of seizures in epilepsy, febrile seizures, unspecified seizures, and complex partial seizures. Additional support for these findings was provided by the concordance results for all categories except male twins reporting complex partial seizure occurrence. However, environmental influences still remained an important factor in seizure expression in these specific categories.

Electronic structure of mott insulators studied by inelastic X-ray scattering

The electronic structure of Mott insulators continues to be a major unsolved problem in physics despite more than 50 years of research. Well-developed momentum-resolved spectroscopies such as photoemission or neutron scattering cannot probe the full Mott gap. High-resolution resonant inelastic x-ray scattering revealed dispersive charge excitations across the Mott gap in a high-critical temperature parent cuprate (Ca(2)CuO(2)Cl(2)), shedding light on the anisotropy of the Mott gap. These charge excitations across the Mott gap can be described within the framework of the Hubbard model.

Phase I dose-finding and pharmacokinetic trial of irinotecan hydrochloride (CPT-11) using a once-every-three-week dosing schedule for patients with advanced solid tumor malignancy

A Phase I study was performed to determine the maximum tolerated dose (MTD), toxicities, and pharmacokinetic profile of irinotecan (CPT-11) and its active metabolites when given on a once-every-3-week schedule. Thirty-four patients with advanced refractory solid malignancies were treated with CPT-11 (240-340 mg/m2) administered as a 90-min i.v. infusion every 3 weeks. Patients were divided into two groups: those with and those without prior abdominal/pelvic (AP) radiotherapy. Gastrointestinal toxicity (nausea, vomiting, and diarrhea) and hematological toxicity (leukopenia and neutropenia) were dose-limiting side effects. Other common toxicities included anorexia, asthenia, and acute cholinergic symptoms (abdominal cramps, diaphoresis, and lacrimation). For patients with no prior AP radiation therapy, the MTD was determined to be 320 mg/m2, whereas those with prior AP radiation therapy had a MTD of 290 mg/m2. Dose-proportional increases in the mean area under the concentration-time curves for CPT-11, SN-38, and SN-38G were not observed over the narrow dose range studied. Mean values of terminal phase half-life, clearance, terminal phase volume of distribution, and steady-state volume of distribution for CPT-11 were 12.4 +/- 1.8 h, 13.0 +/- 3.8 liters/h/m2, 234 +/- 83 liters/m2, and 123 +/- 38 liters/m2, respectively. The pharmacodynamic analyses indicated the strongest correlation to be between SN-38 area under the concentration-time curves and neutropenia (p = 0.60; P = 0.001). A total of five responses (one complete response and four partial responses) were observed in the cohort of 32 patients with previously treated metastatic colorectal carcinoma. In conclusion, gastrointestinal toxicity and hematological toxicity were the dose-limiting toxicities of CPT-11 when administered as a 90-min infusion every 3 weeks. In this trial, the recommended Phase II starting dose for patients with no prior AP radiation therapy was found to be 320 mg/m2; for patients with prior AP radiation, the recommended Phase II starting dose was 290 mg/m2. This once-every-3-week schedule has been incorporated into a Phase I trial of CPT-11 combined with 5-fluorouracil and leucovorin.

Polynuclear chromium(III) carboxylates. 1. Synthesis, structure, and magnetic properties of an octanuclear complex with a ring structure

A novel cyclic octanuclear chromium(III) complex with hydroxo and acetato bridging ligands was isolated and its structure determined by X-ray crystallography. The complex [Cr8(OH)12(OAc)12] (1) (OAc- = CH3CO2-), as found in crystals of 1.34H2O, is obtained by refluxing an aqueous solution of the trinuclear "basic" chromium acetate. 1.34H2O crystallizes in the tetragonal space group I42d with the following unit cell dimensions: a = 16.592(2) A, c = 31.557(4) A, V = 8687(1) A3, and Z = 2. A total of 2000 unique data with I > 3 sigma (I) were used to solve and refine the structure to R(Fo) = 0.066 and Rw(Fo) = 0.085. The structure consists of eight Cr(III) ions that form a ring structure and are bridged by hydroxo and acetato ligands. Each of the two neighboring metal atoms in 1 is bridged either by two OH- ligands and one OAc- ligand, with a Cr...Cr distance of 2.949(2) A, or by two OAc- ligands and one OH- ligand, with a Cr...Cr distance of 3.383(2) A in an alternating fashion. The complex resides on a crystallographic 4 center, and the overall symmetry of 1 is S4. The magnetic susceptibility of 1.34H2O was measured in the temperature range of 5-240 K. Our theoretical modeling of the susceptibility data indicates alternating antiferromagnetic exchange interactions between adjacent spin 3/2 Cr3+ ions around the ring, of magnitude J/kB = 13.7 and 8.9 K, respectively.

Pharmacokinetics, metabolism, and excretion of irinotecan (CPT-11) following I.V. infusion of [(14)C]CPT-11 in cancer patients

This study determined the disposition of irinotecan hydrochloride trihydrate (CPT-11) after i.v. infusion of 125 mg/m(2) (100 microCi) [(14)C]CPT-11 in eight patients with solid tumors. Mean +/- S.D. recovery of radioactivity in urine and feces was 95.8 +/- 2.7% (range 92.2-100.3%, n = 7) of dose. Radioactivity in blood, plasma, urine, and feces was determined for at least 168 h after dosing. Fecal excretion accounted for 63.7 +/- 6.8 (range 54.2-74.9%, n = 7) of dose, whereas urinary excretion accounted for 32.1 +/- 6.9% (range 21.7-43.8%; n = 7) of dose. One patient with a biliary T-tube excreted 30.1% of dose in bile, 14.2% in feces, and 48.2% in urine. Quantitative radiometric HPLC revealed that CPT-11 was the major excretion product in urine, bile, and feces. Aminopentane carboxylic acid (APC) and SN-38 glucuronide (SN-38G) were the most significant metabolites in urine and bile, whereas SN-38 and NPC, a primary amine metabolite, were relatively minor excretion products. SN-38 and APC were the most significant metabolites in feces. The relatively higher amount of SN-38 in feces compared with bile is presumably due to hydrolysis of SN-38G to SN-38 by enteric bacterial beta-glucuronidases. There was close correspondence between quantitative fluorescence HPLC and mass balance findings. CPT-11 was the major circulating component in plasma (55% of the mean radiochemical area under the curve), and CPT-11, SN-38, SN-38G, and APC accounted for 93% of the mean radiochemical AUC. These results show that the parent drug and its three major metabolites account for virtually all CPT-11 disposition, with fecal excretion representing the major elimination pathway.

Exemestane is superior to megestrol acetate after tamoxifen failure in postmenopausal women with advanced breast cancer: results of a phase III randomized double-blind trial. The Exemestane Study Group

PURPOSE

This phase III, double-blind, randomized, multicenter study evaluated the efficacy, pharmacodynamics, and safety of the oral aromatase inactivator exemestane (EXE) versus megestrol acetate (MA) in postmenopausal women with progressive advanced breast cancer who experienced failure of tamoxifen.

PATIENTS AND METHODS

A total of 769 patients were randomized to EXE 25 mg/d (n = 366) or MA (n = 403) 40 mg four times daily. Tumor response, duration of tumor control, tumor-related signs and symptoms (TRSS), quality of life (QOL), survival, and tolerability were evaluated.

RESULTS

Overall objective response (OR) rates were higher in patients treated with EXE than in those treated with MA (15.0% v 12.4%); a similar trend was noted in patients with visceral metastases (13.5% v 10.5%). Median survival time was significantly longer with EXE (median not reached) than with MA (123.4 weeks; P =.039), as were the median duration of overall success (OR or stable disease > or = 24 weeks; 60.1 v 49.1 weeks; P =.025), time to tumor progression (20.3 v 16.6 weeks; P =.037), and time to treatment failure (16.3 v 15.7 weeks; P =.042). Compared with MA, there were similar or greater improvements in pain, TRSS, and QOL with EXE. Both drugs were well tolerated. Grade 3 or 4 weight changes were more common with MA (17.1% v 7.6%; P =.001).

CONCLUSION

EXE prolongs survival time, time to tumor progression, and time to treatment failure compared with MA and offers a well-tolerated treatment option for postmenopausal women with progressive advanced breast cancer who experienced failure of tamoxifen.

Treatment with tumor necrosis factor-alpha and granulocyte-macrophage colony-stimulating factor increases epidermal Langerhans' cell numbers in cancer patients

Dendritic cells (DCs) initiate primary and stimulate secondary T-cell responses. We conducted a phase I trial of tumor necrosis factor (TNF-alpha) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients with cancer to increase DCs in peripheral blood or skin based on in vitro data that showed that CD34(+) hematopoietic precursors require these cytokines to mature into functional antigen-presenting DCs. Eleven patients were treated for 7 days with GM-CSF, 125 microg/m(2) twice daily as subcutaneous injections, and TNF-alpha as a continuous infusion at dose levels of 25, 50, or 100 microg/m(2)/day. The maximum tolerated dose of TNF-alpha was 50 microg/m(2)/day with this dose of GM-CSF; dose-limiting toxicities occurred in both patients treated with 100 microg/m(2)/day. One became thrombocytopenic and the other had transient confusion. Epidermal Langerhans' cells were quantitated by S100 staining of skin biopsies and DC precursors in peripheral blood by colony-forming unit dendritic (CFU-dendritic) assays. S100-positive cells in the epidermis doubled after treatment (2.55 S100(+) cells/high-power field before treatment to 6.05 after treatment, p = 0.029). CFU-dendritic in peripheral blood increased after treatment in 3 colorectal cancer patients but not in 3 patients with melanoma. CD11c(+) or CD123(+), HLA-DR(bright), lineage-negative dendritic cell precursors were not increased in peripheral blood mononuclear cells. This trial demonstrates that treatment with TNF-alpha and GM-CSF can increase the number of DCs in the skin and the number of dendritic cell precursors in the blood of some patients with cancer. This approach may increase the efficacy of vaccination to tumor antigens in cancer patients.

Preventing dental calculus formation in lemurs (Lemur catta, Eulemur fulvus collaris) and baboons (Papio cynocephalus)

The prevention of calculus accumulation in exotic animals is a relatively unexplored topic. A 6-mo study in ring-tailed lemurs (Lemur catta) and collared lemurs (Eulemur fulvus collaris) and two studies in baboons (Papio cynocephalus) (7.5 wks and 6.5 mo) tested the benefits of a primate diet coated with 0.6% sodium hexametaphosphate (HMP) in controlling calculus in these species using a sequential crossover design. The control regimen was an identical, but non-HMP-coated, dry primate chow. At study initiation, the primates were given a thorough dental prophylaxis and provided with the control diet or experimental diet. At the conclusion of the test period, the animals were anesthetized and examined for clinical calculus independently by two examiners. The animals were then given another dental prophylaxis, provided the alternate ration, and the foregoing procedures were repeated. When the animals were provided the HMP-coated diet, significant reductions in calculus formation of 48-62% were observed in the lemurs and the baboons. No clinically significant changes were observed in body weights or in blood chemistry values as a result of ingestion of the HMP-coated regimen.

Phase II study of irinotecan plus cisplatin in patients with advanced non-small-cell lung cancer

PURPOSE

To evaluate the antitumor efficacy and safety of a combination of irinotecan (CPT-11) and cisplatin in patients with inoperable non-small-cell lung cancer (NSCLC). A secondary objective was to characterize the pharmacokinetics and pharmacodynamics of CPT-11 and its active metabolite, SN-38.

PATIENTS AND METHODS

Patients with stage IIIB or IV NSCLC were treated with repeated 4-week courses comprising CPT-11 (60 mg/m(2)) administered on days 1, 8, and 15, and a single dose of cisplatin (80 mg/m(2)) after CPT-11 administration on day 1.

RESULTS

Fifty-two patients were enrolled, including 33 men and 19 women. The median age was 61 years (range, 29 to 79 years). Southwest Oncology Group performance status was 0 in 12 patients, 1 in 32 patients, and 2 in eight patients. Eleven and 41 patients had stage IIIB and IV disease, respectively. Objective responses occurred in 28.8% of patients (15 of 52; 95% confidence interval, 16.5% to 41.2%). The median survival duration was 9.9 months (range, 1.6 to 30.8 months). The 1-year survival rate was 37%. Grade 3/4 adverse events consisted primarily of nausea (32. 7% ) or vomiting (13.5%), late-onset diarrhea (17.3%), and neutropenia (46.1%). The study design led to preferential modification of CPT-11 doses, resulting in CPT-11 dose attenuations to < or = 40 mg/m(2) in the majority of patients (31 of 52; 60%), whereas dose reductions of cisplatin were uncommon. CPT-11 pharmacokinetic parameters were comparable to those reported previously in single-agent studies.

CONCLUSION

CPT-11/cisplatin is an active combination regimen with manageable toxicity in the therapy of stage IIIB/IV NSCLC. Future studies should be designed with schedules and dose modification provisions that avoid unnecessary CPT-11 dose reductions to exploit more directly the therapeutic synergy of these agents.